Powder bed fusion system with point and area scanning laser beams

ABSTRACT

A powder bed fusion system includes a plurality of individual build chambers, with each individual build chamber including an area laser scanner optical device and a point laser scanner. A single, area beam delivery system and the plurality of build chambers are moveable relative to each other, such that the area beam delivery system may be positioned to provide an area scanning laser beam to any of the area laser scanner optical devices in any of the plurality of build chambers. The point laser scanners may be used to contour an edge of an object, and the area scanning laser beam may be used to fill in large areas of the object.

INTRODUCTION

The disclosure generally relates to powder bed fusion system, and amethod of operating the powder bed fusion system.

Powder bed fusion is a class of additive manufacturing processes, inwhich thin layers of material are formed on top of each other to definea three dimensional shape. Powder bed fusion processes may include, butare not limited to, direct metal laser sintering (DMLS), electron beammelting (EBM), selective heat sintering (SHS), selective laser melting(SLM), and selective laser sintering (SLS).

Some powder bed fusion processes use a laser to melt and fuse powderedmaterial together. A thin layer of the powdered material is spread overa powder bed, and the laser is directed onto the powdered material tomelt the powdered material where the laser is applied. The meltedmaterial solidifies, thereby forming a thin cross sectional layer of aproduct. Another layer of the powdered material is spread over thepreviously formed layer, and the laser is directed onto the powderedmaterial to melt the powdered material and fuse it with the underlyinglayer where the laser is applied. The melted material solidifies,thereby forming a slightly thicker cross sectional layer of the product.The process is repeated until the entire three dimensional product isformed.

SUMMARY

A powder bed fusion system is provided. The powder bed fusion systemincludes a plurality of individual build chambers, and a plurality ofarea laser scanner optical devices. One of the plurality of area laserscanner optical devices is dedicated to only one of the plurality ofbuild chambers. An area laser beam generator is operable to generate anarea scanning laser beam. The powder bed fusion system further includesan area beam delivery system that is operatively connected to the arealaser beam generator. The area beam delivery system receives the areascanning laser beam from the area laser beam generator. The area beamdelivery system directs the area scanning laser beam to one of theplurality of area laser scanner optical devices. The area beam deliverysystem and the plurality of individual build chambers are moveablerelative to each other, so that the area beam delivery system may directthe area scanning laser beam to any of the plurality of area laserscanner optical devices in any of the plurality of build chambers.

In one embodiment, the plurality of build chambers are arranged in alinear array, with the area beam delivery system and the linear array ofthe plurality of build chambers moveable relative to each other along alinear path. The area beam delivery system may be moveable relative tothe linear array of the plurality of build chambers.

In one aspect of the disclosure, a track system may moveably support thearea beam delivery system. A drive system may interconnect the tracksystem and the area beam delivery system. The drive system is operableto move the area beam delivery system along the linear path relative tothe track system.

In another embodiment, the plurality of build chambers are arranged inan annular array having an approximate center. The laser beam generatoris disposed at the approximate center of the annular array of theplurality of build chambers. The annular array of the plurality of buildchambers and the area beam delivery system are rotatable relative toeach other about an axis. The area beam delivery system may be rotatableabout the axis relative to the annular array of the plurality of buildchambers.

In one aspect of the disclosure, a turntable may support the area beamdelivery system. A drive system may be connected to the turntable. Thedrive system is operable to rotate the turntable about the axis relativeto the annular array of the plurality of build chambers.

In one aspect of the disclosure, each of the plurality of area laserscanner optical devices focuses the area scanning laser beam onto afirst area equal to or larger than 4.0 mm².

In another aspect of the disclosure, the area beam delivery system mayinclude a pattern control system that is operable to form a pattern inthe area scanning laser beam. The pattern may include at least oneheated area that is heated to a first temperature, and at least onesecond temperature area. The second temperature area may be heated to asecond temperature that is different from the first temperature, or maynot be heated, i.e., an un-heated area.

In another aspect of the disclosure, the powder bed fusion system mayfurther include a plurality of point laser scanners. One of theplurality of point laser scanners is dedicated to only one of theplurality of build chambers. Each of the plurality of point laserscanners focuses a respective point scanning laser beam on a secondarea. The second area is equal to or less than 0.8 mm². In one aspect ofthe disclosure, each of the plurality of point laser scanners includes arespective point laser generator and a respective point laser opticaldevice.

In another aspect of the disclosure, each of the plurality of buildchambers includes a respective powder supply, a respective powderspreader, and a respective powder bed.

A method of operating a powder bed fusion system is also provided. Themethod includes selecting one of a plurality of individual buildchambers as a first active build chamber. A powder is spread over apowder bed in the first active build chamber. A point laser scanner,which is dedicated to the first active build chamber, is activated todirect a point scanning laser beam onto the powder in the powder bed.The point scanning laser beam is moved relative to the powder bed tomelt the powder in the powder bed along a path defining an exterior edgeof a closed shape of a product. An area beam delivery system is movedinto a position adjacent the first active build chamber, such that thearea beam delivery system is positioned to direct an area scanning laserbeam to an area laser scanner optical device that is dedicated to thefirst active build chamber. An area laser beam generator is activated togenerate the area scanning laser beam and direct the area scanning laserbeam to the area beam delivery system. The area beam delivery systemdirects the area scanning laser beam to the area laser scanner opticaldevice of the first active build chamber. The area laser scanner opticaldevice directs the area scanning laser beam onto the powder in thepowder bed to melt the powder within the exterior edge of the closedshape to fill in an interior of the closed shape and define a firstcross sectional layer of the product. The sequencing of the pointscanning laser beam and the area scanning laser beam may vary. The pointscanning laser may be used first to define the exterior edge of theclosed shape, followed by the area scanning laser beam to fill in aninterior of the closed shape. Alternatively, the area scanning laser maybe used to fill in the interior of the closed shape first, followed bythe point scanning laser to define the exterior edge of the closedshape.

In one aspect of the disclosure, the method of operating the powder bedfusion system includes providing the powder bed fusion system to includethe plurality of individual build chambers. The powder bed fusion systemincludes plurality of point laser scanners, with one of the plurality ofpoint laser scanners dedicated to only one of the plurality of buildchambers. Each of the plurality of point laser scanners focuses arespective point scanning laser beam at a second area, which is equal toor less than 0.8 mm². The powder bed fusion system further includes aplurality of area laser scanner optical devices, with one of theplurality of area laser scanner optical devices dedicated to only one ofthe plurality of build chambers. Each of the plurality of area laserscanner optical devices focuses the area scanning laser beam from thearea beam delivery system onto a first area, which is equal to or largerthan 4.0 mm². The powder bed fusion system includes an area laser beamgenerator that is operable to generate an area scanning laser beam. Anarea beam delivery system is operatively connected to the area laserbeam generator for receiving the area scanning laser beam from the arealaser beam generator. The area beam delivery system directs the areascanning laser beam to one of the plurality of area laser scanneroptical devices. The area beam delivery system and the plurality ofindividual build chambers are moveable relative to each other, so thatthe area beam delivery system may direct the area scanning laser beam toany of the plurality of area laser scanner optical devices in any of theplurality of build chambers.

In another aspect of the disclosure, the method of operating the powderbed fusion system includes controlling a pattern control system to forma pattern in the area scanning laser beam. The pattern is controlled tocorrespond to at least a portion of the interior of the closed shape.

In another aspect of the disclosure, the method of operating the powderbed fusion system includes deactivating the area laser beam generator tostop the area scanning laser beam. The area laser scanner optical deviceof the first active build chamber is moveable relative to the powderbed, so that the area laser scanner optical device may be positionedwithin the first active build chamber to direct the area scanning laserbeam onto different regions of the powder bed in the first active buildchamber. The area laser beam generator is then re-activated to generatethe area scanning laser beam, and direct the area scanning laser beamonto the area laser scanner optical device of the first active buildchamber. The area laser scanner optical device directs the area scanninglaser beam onto the powder in the powder bed in the second region, tomelt the powder within the exterior edge of the closed shape to fill inthe interior of the closed shape and further define the first crosssectional layer of the product.

In another aspect of the disclosure, the method of operating the powderbed fusion system includes selecting another one of the plurality ofindividual build chambers as a second active build chamber. A powder isspread over a powder bed in the second active build chamber. A pointlaser scanner, which is dedicated to the second active build chamber, isactivated to direct a point scanning laser beam onto the powder in thepowder bed of the second active build chamber. The point scanning laserbeam of the second active build chamber is moved relative to the powderbed of the second active build chamber to melt the powder in the powderbed along a path defining tan exterior edge of a closed shape of aproduct. The area beam delivery system is moved into a position adjacentthe second active build chamber, such that the area beam delivery systemis positioned to direct the area scanning laser beam to an area laserscanner optical device that is dedicated to the second active buildchamber. The area laser beam generator is activated to generate the areascanning laser beam and direct the area scanning laser beam to the areabeam delivery system. The area beam delivery system directs the areascanning laser beam to the area laser scanner optical device of thesecond active build chamber. The area laser scanner optical device ofthe second active build chamber directs the area scanning laser beamonto the powder in the powder bed of the second active build chamber tomelt the powder within the exterior edge of the closed shape to fill inan interior of the closed shape and define a first cross sectional layerof the product.

Accordingly, the powder bed fusion system uses only a single area laserbeam generator and a single area beam delivery system with multiplebuild chambers. The area beam delivery system is moved between thedifferent build chambers, so that each build chamber does not require anindividual area laser beam generator or an area beam delivery system.Each individual build chamber includes its own point laser scanner. Thepoint laser scanner may be used to contour or define the edge of aclosed shape, and the area laser scanner may be used to fill in theinterior of the closed shape. It should be appreciated that the pointlaser scanner may also be used to fill in the interior of the closedshape, for example, if the area laser scanner is occupied at another oneof the build chambers. The best efficiency may be obtained by directingthe area laser scanner to the build chamber having the largest interiorarea that requires filling. This system optimizes the performancecharacteristics of the point laser scanner and the area laser scanner.

The above features and advantages and other features and advantages ofthe present teachings are readily apparent from the following detaileddescription of the best modes for carrying out the teachings when takenin connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic plan view of a first embodiment of a powder bedfusion system.

FIG. 2 is a schematic plan view of a second embodiment of the powder bedfusion system.

FIG. 3 is a schematic cross sectional view of a build chamber of thepowder bed fusion system.

DETAILED DESCRIPTION

Those having ordinary skill in the art will recognize that terms such as“above,” “below,” “upward,” “downward,” “top,” “bottom,” etc., are useddescriptively for the figures, and do not represent limitations on thescope of the disclosure, as defined by the appended claims. Furthermore,the teachings may be described herein in terms of functional and/orlogical block components and/or various processing steps. It should berealized that such block components may be comprised of any number ofhardware, software, and/or firmware components configured to perform thespecified functions.

Referring to the Figures, wherein like numerals indicate like partsthroughout the several views, a powder bed fusion system is generallyshown at 20. The powder bed fusion system 20 is used to employ anadditive manufacturing process. In general, as known to those skilled inthe art, the additive manufacturing process includes developing a threedimensional computer model of a product, and then slicing the threedimensional model into thin slices to define multiple cross sectionallayers. A thin layer of a powdered material 34 is then applied to abuild platform, and a laser beam is used to fuse the powdered material34 at the location(s) the laser beam is applied. The location and/orpath that the laser beam is applied is defined by each respective crosssectional layer of the three dimensional product. Another layer of thepowdered material 34 is applied over the first, and the laser beam isused to fuse the second layer of powdered material 34 to the fused crosssectional layer beneath. The process is repeated for each crosssectional layer, thereby building up the three dimensional product. Thepowdered material 34 may include metals, alloys, plastics, composites,or some other material not described herein. The powder bed fusionsystem 20 may be used to manufacture any type and/or configuration ofproduct that is manufactured from a material capable of being used inthe additive manufacturing process, and is capable of being formed bythe additive manufacturing process. The specific type, shape, and/orconfiguration of the product are not pertinent to the teachings of thisdisclosure, and are therefore not described in detail herein.

Referring to FIGS. 1 and 2, the powder bed fusion system 20 includes aplurality of individual build chambers 22. As shown in the Figures, thepowder bed fusion system 20 includes a first build chamber 22A, a secondbuild chamber 22B, a third build chamber 22C, a fourth build chamber22D, and a fifth build chamber 22E. The powder bed fusion system 20shown in FIG. 2 further includes a sixth build chamber 22F. The buildchambers 22 are referred to generally herein by the reference numeral22, and are referred to specifically herein and shown in the Figures bythe respective reference numerals, i.e., 22A-22F. In some embodiments,the individual build chambers 22 may be configured identically to eachother. In other embodiments, the individual build chambers 22 may beconfigured differently from each other. However, each of the individualbuild chambers 22 are equipped with the same general equipment forperforming the same general process.

Referring to FIG. 3, each of the build chambers 22 includes a respectivepowder supply 24, a respective powder spreader 26, and a respectivepowder bed 28 or build platform. The powder supply 24, the powderspreader 26, and the build platform may be configured in any suitablemanner. In the exemplary embodiment shown in FIG. 3, the powder supply24 is contained in a chamber with a moveable floor 30. The floor 30moves upward in a vertical direction, generally indicated by arrow 32,to present the powdered material 34 to the powder spreader 26 for eachcross sectional layer to be applied. The powder spreader 26 may includea roller, a scraper, or some other similar device. The powder spreader26 scrapes off a layer of the powdered material 34, and spreads isacross the powder bed 28 in a thin layer. Once that layer of powderedmaterial 34 is fused together, the powder bed 28 is lowered, generallyindicated by arrow 36, the equivalent of one cross sectional thickness,and the floor 30 of the powder supply 24 is again raised to resupply thepowder spreader 26 so that the process may be repeated. It should beappreciated that the individual build chambers 22 may differ inconstruction and operation from the exemplary embodiment shown anddescribed herein and that the exemplary embodiment of the build chamber22 shown in FIG. 3 and described herein is provided merely as an exampleof one possible embodiment of the build chambers 22.

Each of the build chambers 22 includes a respective point laser scanner38. As such, the powder bed fusion system 20 includes a plurality ofpoint laser scanners 38, with one of the point laser scanners 38dedicated to only one of the individual build chambers 22. Each of thepoint laser scanners 38 includes a respective point laser generator 40,and a respective point laser optical device 42. The point laser scanners38 operate as is known in the art. Generally, the point laser generator40 is operable to generate a point scanning laser beam, and the pointlaser optical device 42 is operable to focus the point scanning laserbeam on the powder bed 28 of its respective build chamber 22. The pointlaser optical device 42 is moveable within the build chamber 22 to moveor direct the point scanning laser beam on the powder bed 28. Each ofthe point laser scanners 38 focuses their respective point scanninglaser beam on a point area, hereinafter referred to as a second area.The second area covered by the point scanning laser beam has an areathat is equal to or less than 0.8 mm². In some embodiments, the secondarea is equal to or less than 0.04 mm². The specific type, configurationand operation of the point laser scanners 38 are not pertinent to theteachings of this disclosure, and are therefore not described in detailherein.

Each of the individual build chambers 22 includes a respective arealaser scanner optical device 44. Accordingly, the powder bed fusionsystem 20 includes a plurality of area laser scanner optical devices 44,with one of the plurality of area laser scanner optical devices 44dedicated to only one of the plurality of build chambers 22. Each of thearea laser scanner optical devices 44 cooperates with a single area beamdelivery system 46 and a single area laser beam generator 47 to form anarea laser scanner. The area laser scanner operates as is known in theart. In general, the area laser beam generator 47 is operable togenerate an area scanning laser beam, and the respective area laserscanner optical devices 44 are operable to focus the area scanning laserbeam on the powder bed 28 of its respective build chamber 22. The areabeam delivery system 46 receives the area scanning laser beam from thearea laser beam generator 47, and directs the area scanning laser beamto one of the area laser scanner optical devices 44 in one of theplurality build chambers 22. The area laser scanner optical devices 44may be moveable within their respective build chamber 22 to move ordirect the area scanning laser beam on the powder bed 28. Each of thearea laser scanner optical devices 44 focuses their respective areascanning laser beam on an area, hereinafter referred to as a first area.The first area covered by the area scanning laser beam has an area thatis equal to or larger than 4.0 mm². In some embodiments, the first areais equal to or larger than 25.0 mm². Accordingly, the point laseroptical devices 42 focus their respective point scanning laser beam at avery small area, e.g., 0.04 mm² (approximately 100 microns), whereas thearea laser scanner optical devices 44 focus their respective areascanning laser beam at a much larger area, e.g., at least 4.0 mm², orapproximately 100 times larger than the point scanning laser beam.

As shown in FIGS. 1 and 2, the powder bed fusion system 20 includes onlythe single area beam delivery system 46 and the single area laser beamgenerator 47. As such, the area laser beam generator 47 and the areabeam delivery system 46 are shared with the area laser scanner opticaldevice 44 of each of the individual build chambers 22 to complete thearea laser scanner. The area laser beam generator 47 produces the areascanning laser beam, which covers a much larger area than the pointlaser scanner 38. The area laser beam generator 47 may be stationaryrelative to the area beam delivery system 46, or may be moveable withthe area beam delivery system 46. The area scanning laser beam may bedirected to the area beam delivery system 46 through the air, via afiber optic cable, or some other suitable transmission medium. In oneembodiment, the area beam delivery system 46 directs the area scanninglaser beam to the respective area laser scanner optical devices 44through the air. In other embodiments, however, the area beam deliverysystem 46 may direct the area scanning laser beam to the respective arealaser scanner optical devices 44 through a fiber optic cable or othersuitable transmission medium.

The area beam delivery system 46 may include a pattern control system48, which is operable to form a pattern in the area scanning laser beamon the powder bed 28. The pattern may include at least one heated areaand at least one second temperature area. The at least one heated areamay be heated to a first temperature, which is different than the secondtemperature area. The second temperature area may be heated to a secondtemperature, or may not be heated at all, i.e., the second temperaturearea may include an un-heated area. The pattern control system 48 may beused to form intricate patterns in the area scanning laser beam, whichare applied over a large area of the powder bed 28. The area laser beamgenerator 47, the beam delivery system 46, the pattern control system48, and the area laser scanner optical devices 44, may be configured inany suitable manner, and are known to those skilled in the art. Thespecific type, configuration and operation of the area laser beamgenerator 47, the area beam delivery system 46, the pattern controlsystem 48, and the area laser scanner optical devices 44 are notpertinent to the teachings of this disclosure, and are therefore notdescribed in detail herein.

The area beam delivery system 46 and the plurality of individual buildchambers 22 are moveable relative to each other, such that the area beamdelivery system 46 is operable to provide the area scanning laser beamto any of the area laser scanner optical devices 44 in any of theindividual build chambers 22. The build chambers 22 and the area beamdelivery system 46 may be arranged and connected in any suitable mannerthat allows the area beam delivery system 46 and/or the individual buildchambers 22 to move relative to each other, so that the area laserscanner optical devices 44 of each individual build chamber 22 may bepositioned to receive the area scanning laser beam from the beamdelivery system 46. It should be appreciated that the area beam deliverysystem 46 may be moveable relative to the plurality of build chambers22, that the plurality of build chambers 22 may be moveable relative tothe area beam delivery system 46, or that both the area beam deliverysystem 46 and the build chambers 22 move relative to each other.

Referring to FIG. 1, a first exemplary embodiment of the powder bedfusion system 20 is shown. As shown in FIG. 1, the plurality of buildchambers 22 are arranged in a linear array, with the area beam deliverysystem 46 and the linear array of the plurality of build chambers 22moveable relative to each other along a linear path 50. Morespecifically, the area beam delivery system 46 is moveable relative tothe linear array of the plurality of build chambers 22 along the linearpath 50. The powder bed fusion system 20 may include a track system 52or other similar structure that moveably supports the area beam deliverysystem 46. A drive system 54 may interconnect the track system 52 andthe area beam delivery system 46. The drive system 54 is operable tomove the area beam delivery system 46 along the linear path 50 relativeto the track system 52. The drive system 54 may include one or moreelectric motors, hydraulics, pneumatics, all hosing, piping, supports,controls, etc., necessary to move the area beam delivery system 46 alongthe track system 52.

Referring to FIG. 2, a second exemplary embodiment of the powder bedfusion system 20 is shown. As shown in FIG. 2, the plurality of buildchambers 22 are arranged in an annular array having an approximatecenter 56, with the area laser beam generator 47 disposed at theapproximate center 56 of the annular array of the plurality of buildchambers 22. The annular array of the plurality of build chambers 22 andthe area beam delivery system 46 are rotatable relative to each otherabout an axis 58. The axis 58 is disposed at the approximate center 56of the annular array. More specifically, the area beam delivery system46 is rotatable about the axis 58 relative to the annular array of theplurality of build chambers 22. The powder bed fusion system 20 mayinclude a turntable 60 supporting the area beam delivery system 46. Adrive system 54 may be connected to the turntable 60. The drive system54 is operable to rotate the turntable 60 about the axis 58 relative tothe annular array of the plurality of build chambers 22. The drivesystem 54 may include one or more electric motors, hydraulics,pneumatics, all hosing, piping, supports, controls, etc., necessary torotate the turntable 60 about the axis 58, relative to the individualbuild chambers 22.

A method of operating the powder bed fusion system 20 is also provided.The method optimizes the use of the point scanning laser and the areascanning laser. Because the point scanning laser directs the pointscanning laser beam to a small area, i.e., the second are, it works wellfor defining sharp, crisp edges or lines. However, due to the smallpoint area, i.e., the second area, the point scanning laser is very slowfor filling in large areas. However, because the area scanning laserprojects the area scanning laser beam onto a much larger area, the areascanning laser works well for quickly filling in areas. Accordingly, themethod described below, uses the respective point scanning laser of eachindividual build chamber 22 for contouring or edging a part, and usesthe single area laser beam generator 47 and the single area beamdelivery system 46 in cooperation with the respective area laser scanneroptical device 44 of each individual build chamber 22 for filling in theinteriors of the part.

The method includes providing the powder bed fusion system 20. Thepowder bed fusion system 20 may be configured differently than shown inthe Figures or described herein. However, it should be appreciated thatthe powder bed fusion system 20 includes the plurality of individualbuild chambers 22. Each of the individual build chambers 22 includes arespective point laser scanner 38. Each of the respective point laserscanners 38 focuses a respective point scanning laser beam at the secondarea, which is equal to or less than 0.8 mm². Each of the individualbuild chambers 22 further includes a respective area laser scanneroptical device 44. Each of the respective area laser scanner opticaldevices 44 focuses the area scanning laser beam from the area beamdelivery system 46 onto the first area, which is equal to or larger than4.0 mm². The powder bed fusion system 20 provided further includes thesingle, area laser beam generator 47, and the single area beam deliverysystem 46. At least one of the area beam delivery system 46 and theplurality of individual build chambers 22 are configured to be moveablerelative to the other other, such that the area beam delivery system 46is operable to provide the area scanning laser beam to any of theplurality of area laser scanner optical devices 44 in any of theplurality of build chambers 22.

One of the individual build chambers 22 as selected as a first activebuild chamber. As used herein, the first active build chamber is definedas the first build chamber 22A. The powder spreader 26 spreads thepowdered material 34 over the powder bed 28 in the first active buildchamber 22A. The respective point laser scanner 38 dedicated to thefirst active build chamber 22A is then activated to direct the pointscanning laser beam onto the powdered material 34 in the powder bed 28of the first active build chamber 22A. The point scanning laser beam ismoved relative to the powder bed 28 to melt the powder in the powder bed28 along a path defining an exterior edge of a closed shape of a firstproduct within the first active build chamber 22A. As such, the pointscanning laser beam is used to edge or contour the exterior or outeredge of the first product.

The area beam delivery system 46 is moved into a position adjacent thefirst active build chamber 22A, such that the area beam delivery system46 is positioned to direct the area scanning laser beam to the arealaser scanner optical device 44 dedicated to the first active buildchamber 22A. The area laser beam generator 47 is then activated togenerate the area scanning laser beam, and direct the area scanninglaser beam to the area beam delivery system 46. The area beam deliverysystem 46 then directs the area scanning laser beam to the area laserscanner optical device 44 of the first active build chamber 22A. Thepattern control system 48 may be controlled to adjust or define apattern in the area scanning laser beam projected onto the powder bed 28of the first active build chamber 22A. The pattern may correspond to atleast a portion of the interior of the closed shape defining theproduct. The area laser scanner optical device 44 directs the areascanning laser beam onto a first region of the powder in the powder bed28, to melt the powder within the exterior edge of the closed shape tofill in an interior of the closed shape and at least partially defineone cross sectional layer of the first product. The sequencing of thepoint scanning laser beam and the area scanning laser beam may vary. Thepoint scanning laser may be used first to define the exterior edge ofthe closed shape, followed by the area scanning laser beam to fill in aninterior of the closed shape. Alternatively, the area scanning laser maybe used to fill in the interior of the closed shape first, followed bythe point scanning laser to define the exterior edge of the closedshape.

The area laser beam generator may then be deactivated. If necessary, thearea laser scanner optical device 44 of the first active build chamber22A may be moved relative to the powder bed 28 into a second region, sothat the area laser scanner optical device 44 is positioned to directthe area scanning laser beam onto a different region of the powder bed28 of the first active build chamber 22A, i.e., the second region. Oncethe area laser scanner optical device 44 is repositioned, the area laserbeam generator 47 is re-activated to generate the area scanning laserbeam and direct the area scanning laser beam to the area laser scanneroptical device 44 of the first active build chamber 22A. The area laserscanner optical device 44 may be repositioned as many times as necessaryto fill in the closed shape of the first product. For example, the arealaser scanner optical device 44 may be repositioned in a raster or gridconfiguration as needed.

Once the first cross sectional layer of the first product is formed, thearea beam delivery system 46 may be moved to a different build chamber22 while the first cross sectional layer of the first product cools.Alternatively, the area beam delivery system 46 may remain positionedadjacent the first active build chamber 22A to form a second crosssectional layer of the first product in the first active build chamber22A. If the area beam delivery system 46 remains positioned adjacent thefirst active build chamber 22A, then the above describe process isrepeated as necessary to completely form the first product.

The above described process may be repeated for each of the individualbuild chambers 22 in turn. For example, once the area beam deliverysystem 46 is finished with the first active build chamber 22A, while thefirst cross sectional layer of the first product cools or when the firstproduct is complete, another one of the plurality of individual buildchambers 22 is selected as a second active build chamber. As usedherein, the second active build chamber is defined as the second buildchamber 22B. Similar to the process described above, the powderedmaterial 34 is spread over the respective powder bed 28 in the secondactive build chamber 22B, with the respective powder spreader 26 of thesecond active build chamber 22B. The respective point laser scanner 38dedicated to the second active build chamber 22B is then activated todirect the point scanning laser beam onto the powdered material 34 inthe powder bed 28 of the second active build chamber 22B. The pointscanning laser beam is moved relative to the powder bed 28 to melt thepowder in the powder bed 28 along a path defining an exterior edge of aclosed shape of a second product within the second active build chamber22B. As such, the point scanning laser beam in the second active buildchamber 22B is used to edge or contour the exterior or outer edge of thesecond product.

The area beam delivery system 46 is moved into a position adjacent thesecond active build chamber 22B, such that the area beam delivery system46 is positioned to direct the area scanning laser beam to the arealaser scanner optical device 44 dedicated to the second active buildchamber 22B. The area laser beam generator 47 is then activated togenerate the area scanning laser beam, and direct the area scanninglaser beam to the area beam delivery system 46. The area beam deliverysystem 46 then directs the area scanning alder beam to the area laserscanner optical device 44 of the second active build chamber 22B. Thepattern control system 48 may be controlled to adjust or define apattern in the area scanning laser beam projected onto the powder bed 28of the second active build chamber 22B. The pattern may correspond to atleast a portion of the interior of the closed shape defining the secondproduct. The area laser scanner optical device 44 directs the areascanning laser beam onto a second region of the powder in the powder bed28, to melt the powder within the exterior edge of the closed shape tofill in an interior of the closed shape and at least partially defineone cross sectional layer of the second product. The above describeprocess is repeated as necessary to completely form the second product.

The detailed description and the drawings or figures are supportive anddescriptive of the disclosure, but the scope of the disclosure isdefined solely by the claims. While some of the best modes and otherembodiments for carrying out the claimed teachings have been describedin detail, various alternative designs and embodiments exist forpracticing the disclosure defined in the appended claims.

What is claimed is:
 1. A powder bed fusion system comprising: aplurality of individual build chambers; an area laser beam generatoroperable to generate an area scanning laser beam; a plurality of arealaser scanner optical devices, with one of the plurality of area laserscanner optical devices dedicated to only one of the plurality of buildchambers; and an area beam delivery system operatively connected to thearea laser beam generator for receiving the area scanning laser beamfrom the area laser beam generator and directing the area scanning laserbeam to one of the plurality of area laser scanner optical devices;wherein the area beam delivery system and the plurality of individualbuild chambers are moveable relative to each other, such that the areabeam delivery system is operable to direct the area scanning laser beamto any of the plurality of area laser scanner optical devices in any ofthe plurality of build chambers.
 2. The powder bed fusion system setforth in claim 1, wherein the plurality of build chambers are arrangedin a linear array, with the area beam delivery system and the lineararray of the plurality of build chambers moveable relative to each otheralong a linear path.
 3. The powder bed fusion system set forth in claim2, wherein the area beam delivery system is moveable relative to thelinear array of the plurality of build chambers.
 4. The powder bedfusion system set forth in claim 3, further comprising a track systemmoveably supporting the area beam delivery system.
 5. The powder bedfusion system set forth in claim 4, further comprising a drive systeminterconnecting the track system and the area beam delivery system,wherein the drive system is operable to move the area beam deliverysystem along the linear path relative to the track system.
 6. The powderbed fusion system set forth in claim 1, wherein the plurality of buildchambers are arranged in an annular array having an approximate center,with the area laser beam generator disposed at the approximate center ofthe annular array of the plurality of build chambers, and with theannular array of the plurality of build chambers and the area beamdelivery system rotatable relative to each other about an axis.
 7. Thepowder bed fusion system set forth in claim 6, wherein the area beamdelivery system is rotatable about the axis relative to the annulararray of the plurality of build chambers.
 8. The powder bed fusionsystem set forth in claim 7, further comprising a turntable supportingthe area beam delivery system.
 9. The powder bed fusion system set forthin claim 8, further comprising a drive system connected to theturntable, wherein the drive system is operable to rotate the turntableabout the axis relative to the annular array of the plurality of buildchambers.
 10. The powder bed fusion system set forth in claim 1, whereineach of the plurality of area laser scanner optical devices focuses thearea scanning laser beam onto a first area equal to or larger than 4.0mm².
 11. The powder bed fusion system set forth in claim 1, wherein thearea beam delivery system includes a pattern control system operable toform a pattern in the area scanning laser beam, such that the patternincludes at least one heated area that is heated to a first temperature,and at least one second temperature area having a second temperaturethat is different from the first temperature.
 12. The powder bed fusionsystem set forth in claim 1, further comprising a plurality of pointlaser scanners, with one of the plurality of point laser scannersdedicated to only one of the plurality of build chambers.
 13. The powderbed fusion system set forth in claim 12, wherein each of the pluralityof point laser scanners focuses a respective point scanning laser beamon a second area equal to or less than 0.8 mm².
 14. The powder bedfusion system set forth in claim 12, wherein each of the plurality ofpoint laser scanners includes a respective point laser generator and arespective point laser optical device.
 15. The powder bed fusion systemset forth in claim 1, wherein each of the plurality of build chambersincludes a respective powder supply, a respective powder spreader, and arespective powder bed.
 16. A method of operating a powder bed fusionsystem, the method comprising: selecting one of a plurality ofindividual build chambers as a first active build chamber; spreading apowder over a powder bed in the first active build chamber; activating apoint laser scanner dedicated to the first active build chamber todirect a point scanning laser beam onto the powder in the powder bed;moving the point scanning laser beam relative to the powder bed to meltthe powder in the powder bed along a path defining an exterior edge of aclosed shape of a product; moving an area beam delivery system into aposition adjacent the first active build chamber such that the area beamdelivery system is positioned to direct an area scanning laser beam toan area laser scanner optical device dedicated to the first active buildchamber; activating an area laser beam generator to generate the areascanning laser beam and direct the area scanning laser beam to the areabeam delivery system; directing the area scanning laser beam from thearea beam delivery system to the area laser scanner optical device ofthe first active build chamber, whereby the area laser scanner opticaldevice directs the area scanning laser beam onto the powder in thepowder bed to melt the powder within the exterior edge of the closedshape to fill in an interior of the closed shape and define one layer ofthe product.
 17. The method set forth in claim 16, further comprisingproviding the powder bed fusion system to include: a plurality ofindividual build chambers; a single, area laser beam generator operableto generate the area scanning laser beam; a plurality of point laserscanners, with one of the plurality of point laser scanners dedicated toonly one of the plurality of build chambers, wherein each of theplurality of point laser scanners focuses a respective point scanninglaser beam at a second area equal to or less than 0.8 mm²; a pluralityof area laser scanner optical devices, with one of the plurality of arealaser scanner optical devices dedicated to only one of the plurality ofbuild chambers, wherein each of the plurality of area laser scanneroptical devices focuses the area scanning laser beam onto a first areaequal to or larger than 4.0 mm²; and an area beam delivery systemoperatively connected to the area laser beam generator for receiving thearea scanning laser beam from the area laser beam generator anddirecting the area scanning laser beam to one of the plurality of arealaser scanner optical devices, wherein the area beam delivery system andthe plurality of individual build chambers are moveable relative to eachother, such that the area beam delivery system is operable to direct thearea scanning laser beam to any of the plurality of area laser scanneroptical devices in any of the plurality of build chambers.
 18. Themethod set forth in claim 16, further comprising controlling a patterncontrol system to form a pattern in the area scanning laser beam tocorrespond to at least a portion of the interior of the closed shape.19. The method set forth in claim 16, further comprising: deactivatingthe area laser beam generator; moving the area laser scanner opticaldevice dedicated to the first active build chamber relative to thepowder bed of the first active build chamber so that the area laserscanner optical device is positioned to direct the area scanning laserbeam onto a different region of the powder bed; and re-activating thearea laser beam generator to generate the area scanning laser beam anddirect the area scanning laser beam onto the area laser scanner opticaldevice of the first active build chamber, whereby the area laser scanneroptical device directs the area scanning laser beam onto the powder inthe powder bed in the second region to melt the powder within theexterior edge of the closed shape to fill in the interior of the closedshape and define one layer of the product.
 20. The method set forth inclaim 16, further comprising: selecting another one of the plurality ofindividual build chambers as a second active build chamber; spreading apowder over a powder bed in the second active build chamber; activatinga point laser scanner dedicated to the second active build chamber todirect a point scanning laser beam onto the powder in the powder bed ofthe second active build chamber; moving the point scanning laser beam ofthe second active build chamber relative to the powder bed to melt thepowder in the powder bed along a path defining an exterior edge of aclosed shape of a product; moving the area beam delivery system into aposition adjacent the second active build chamber such that the areabeam delivery system is positioned to direct the area scanning laserbeam to an area laser scanner optical device dedicated to the secondactive build chamber; and activating the area laser beam generator togenerate the area scanning laser beam and direct the area scanning laserbeam onto the area laser scanner optical device of the second activebuild chamber, whereby the area laser scanner optical device directs thearea scanning laser beam onto the powder in the powder bed of the secondactive build chamber to melt the powder within the exterior edge of theclosed shape to fill in an interior of the closed shape and define onelayer of the product.